补阳还五汤对紫杉醇诱导的大鼠外周神经痛模型的治疗作用与其机制的探究

Antiallodynic Effect of Buyang Huanwu Decoction on Paclitaxel-induced Peripheral Neuropathic Pain in Rats and Its Mechanism

目的观察补阳还五汤对紫杉醇(paclitaxel,PTX)诱导的大鼠外周神经痛(PTX-induced peripher-al neuropathic pain,PIPNP)的治疗作用,并探究其对脊髓大麻素Ⅱ型受体(CBR2)-脊髓星形胶质细胞(GFAP)-炎症因子(TNF-α、IL-β)通路的影响。方法将60只雄性SD大鼠平均分为对照组、模型组、治疗组和AM630组4组,每组15只。除对照组外,其余各组于实验第1、3、5、7天分别腹腔注射PTX 2 mg/kg,于第14天建立稳定的外周神经痛模型。治疗组在建模后予补阳还五汤2.5 g/kg灌胃连续治疗14天。AM630组在治疗组的基础上每天于灌胃前予CBR2阻滞剂AM630腹腔注射3 mg/kg。疼痛行为学测试采用UP and Down法测试大鼠机械缩足阈值(mechanical withdraw threshold,MWT)。采用免疫组化、Western Blot检测CBR2和GFAP表达情况,采用ELISA试剂盒检测脊髓炎症因子IL-1β和TNF-α蛋白含量。结果与对照组比较,模型组MWT值显著降低(P<0.01);与模型组比较,治疗组MWT显著增高(d20~d28,P<0.05,P<0.01),AM630组MWT差异无统计学意义(P>0.05)。与对照组比较,模型组CBR2表达差异无统计学意义(P>0.05),GFAP、TNF-α、IL-β表达量均增高(P<0.01);与模型组比较,治疗组CBR2表达量增加(P<0.01),GFAP、TNF-α、IL-β表达量均降低(P<0.01),AM630组以上蛋白表达差异无统计学意义(P>0.05)。结论补阳还五汤可治疗PIPNP,其可通过激活CBR2并下调GFAP活化和炎症因子释放介导镇痛作用。

Objective To observe antiallodynic effects of Buyang Huanwu Decoction(BYHWD)on paclitaxel-in-duced peripheral neuropathic pain(PIPNP)in model rats and its effects on cannabinoid receptorⅡ(CBR2)-astrocyte-in-flammatory factors(TNF-αand IL-β)pathway.Methods Sixty male Sprague-Dawley rats were equally divided into 4 groups,the control group,the model group,the therapy group,and the AM630 group,15 in each group.Except the control group,rats in the rest groups were intraperitoneally injected with paclitaxel(2 mg/kg)at day 1,3,5,7,respectively,and a stable peripheral neuralgia model was established on the 14th day.The therapy group was administered with BYHWD(2.5 g/kg)by gastrogavage for 14 days after modeling.The AM630 group was given intraperitoneal injection of cannabinoid receptorⅡantagonist AM630(3 mg/kg)each day before treatment.Mechanical withdraw threshold(MWT)was tested by UP and Down method.The protein expression levels of CBR2 and glial fibrillary acidic protein(GFAP)in the spinal cord were assayed by immunohistochemistry and Western Blot.The protein contents of IL-1βand TNF-αin the spinal cord were assayed by ELISA.Results Compared with the control group,MWTs significantly decreased in model group(P<0.01).Compared with the model group,MWTs significantly increased in the therapy group(day 20-day 28,P<0.05,P<0.01),but with no statistical differences in the AM630 group(P>0.05).Compared with the control group,the protein expression level of CBR2 had no statistical differences(P>0.05),and the levels of GFAP,IL-1β,and TNF-αincreased(P<0.01)in the model group.Compared with the model group,the protein expression level of CBR2 increased(P<0.01),and the ex-pression levels of GFAP,IL-1β,and TNF-αdecreased(P<0.01)in the therapy group,but with no statistical differences in the AM630 group(P>0.05).Conclusion BYHWD treated PIPNP,and it mediated analgesia effects by activating spinal CBR2 and down-regulated activation of GFAP and the release of inflammatory cytokines.